1-[4-(5-cyanoindol-3-yl)butyl]-4-(2-carbamoyl-benzofuran-5-yl)-piperazine, the hydrochloride salt of which is commonly known as vilazodone, is a dual selective serotonin reuptake inhibitor (SSRI)/5HT1A receptor partial agonist. Vilazodone can be used, for example, to treat major depressive disorders.
U.S. Pat. No. 5,532,241 discloses a method of preparing vilazodone. In this method, 3-(4-chlorobutyl)-5-cyanoindole is one of the key intermediates, which can be obtained by reaction of 5-cyanoindole with 4-chlorobutyryl chloride.